package com.itheima.youdianda.filter;

import com.alibaba.fastjson.JSON;
import com.itheima.youdianda.common.BaseContext;
import com.itheima.youdianda.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经登录
 * @Author Pan Rundong
 */
@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    /**
     * 路径匹配器，支持通配符
     */
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    /**
     * 登录过滤器
     * @param servletRequest
     * @param servletResponse
     * @param filterChain
     * @throws IOException
     * @throws ServletException
     */
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;


        //1. 获取本次请求的URI
        String requestURI = request.getRequestURI();

        log.info("拦截到请求：{}", requestURI);

        //定义放行url
        String [] urls = new String[]{
                "/doc.html",
                "/webjars/**",
                "/swagger-resources",
                "/v2/api-docs",
                "/dist/**",
                "/pc/**",
                "/index/**",
                "/sys_menu/**",
                "/sys_role/**",
                "/sys_menu/**",
                "/sys_user/**",
                "/ydd_article/**",
                "/ydd_tag/**",
                "/ydd_cate/**",
                "/ydd_user/**",
                "/admin/ydd_link/**",
                "/index/**",
                "/sys_menu/**",
                "/sys_role/**",
                "/sys_user/**",
                "/sys_config/**",
                "/sys_menu/**",
                "/ydd_advimg/**",
                "/ydd_advpos/**",
                "/admin/**",
                "/ydd_link/**",
                "/sys_menu/**",
                "/home/**",
                "/user/**",
                "/common/**"
        };
        /**
         * 注意：
         *     @WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
         *          这里的/*是由tomcat解析，支持任意路径的匹配
         *     /backend/** 这里的通配符是由spring工具类 AntPathMatcher 解析
         *          /backend/*   里面的*代表的是一层目录任意
         *          /backend/**  里面的**代表多层任意目录
         */


        //2. 判断本次请求是否需要处理
        boolean check = check(urls, requestURI);

        //3. 如果不需要处理，则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }

        //4-1. 判断登录状态，如果已登录，则直接放行
//        if (request.getSession().getAttribute("") != null) {
//            log.info("用户已登录，用户id为：{}",request.getSession().getAttribute("employee"));
//
//            //获取线程中用户的id
//            Long empId = (Long) request.getSession().getAttribute("employee");
//            BaseContext.setCurrentId(empId);
//
//            filterChain.doFilter(request,response);
//            return;
//        }


        log.info("用户未登录");
        //5. 如果未登录则返回未登录结果
        response.getWriter().write(JSON.toJSONString(R.error("")));

    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String [] urls, String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }
        }
        return false;
    }
}
